JP4014067B2 - Capacitor power storage system remaining amount detection device - Google Patents

Description

[0001]
The present invention relates to a remaining amount detection device for a capacitor power storage system that performs power storage by connecting a plurality of capacitors in series and parallel.
[0002]
[Prior art]
An ECS (Energy Capacitor System) power storage device using an electric double layer capacitor has attracted attention as a power supply device for electric vehicles and a large-scale power storage device. Since the electric double layer capacitor is a physical charge similar to other capacitors compared to a chemical battery such as a lead battery or a nickel-cadmium battery that takes time to charge, it can be rapidly charged. Moreover, the electric double layer capacitor has a merit not found in a chemical battery that a large amount of energy can be released in a short time. However, a chemical battery is a constant voltage device, and even if power is supplied to a load in the normal operating range, the terminal voltage shows a constant voltage characteristic regardless of the amount of energy stored in the battery. Te, an electric double layer capacitor, when by increasing the storage amount of the power to attempt to effectively utilize it, has the characteristic that the terminal voltage varies greatly based on the relationship Q = CV ^2/2. In other words, the terminal voltage of the electric double layer capacitor changes greatly from fully charged voltage to zero as the stored energy is discharged, and in order to supply a stable rated voltage to the load, the output voltage is greatly adjusted by ECS. Is required.
[0003]
ECS has already been developed as a power energy storage system consisting of a capacitor, a parallel monitor, and a current pump (for example, electronic technology, 1994-12, p1 to 3, Electrology B, Vol. 115, No. 5, 1995, p504 to 610, Okamura Ikuo, “Electric Double Layer Capacitor and Power Storage System”, published by Nikkan Kogyo Shimbun, March 31, 1999, first edition, first print, p6-14, p145-159, etc.). Here, the parallel monitor is connected between terminals of each capacitor bank in which a plurality of capacitors are connected in series and parallel, and when the charge voltage of the capacitor bank exceeds the set value of the parallel monitor, the charge current is bypassed, It is a device that detects full charge.
[0004]
The capacitor bank with the parallel monitor can be initialized by bypassing the charging current so that the charging voltage of the capacitor bank does not rise above a set value when charging. All the capacitors are charged evenly to a set voltage, and the storage capacity of the capacitors can be exhibited almost 100%. Therefore, the parallel monitor can equalize the maximum voltage, prevent backflow, detect and control the end-of-charge voltage, etc., even when there are variations in capacitor characteristics and residual charge, so that it can be used to the full withstand voltage. As such, it has an extremely important role and is an indispensable device for effective use of energy density.
[0005]
[Problems to be solved by the invention]
As power storage systems (ECS) that combine capacitors and electronic circuits continue to increase in size, as a means to reduce significant changes in output voltage caused by charging / discharging as it is, connection of capacitors such as switching of capacitors in series / parallel connection is possible. The method of switching and using is being put into practical use. However, such a power supply apparatus has a problem that the remaining amount of energy stored in the power supply cannot be displayed correctly. That is, in an electric double layer capacitor battery, a terminal voltage is usually detected using a voltmeter and displayed as a remaining amount. Therefore, when the energy is taken out in parallel connection from the fully charged state and when the voltage drops and switched from parallel connection to series connection, the remaining amount of energy is less in the latter even if the voltage is almost the same. Nevertheless, the remaining amount of energy detected by the voltmeter will be the same.
[0006]
[Means for Solving the Problems]
The present invention solves the above-described problems, and enables the remaining amount to be measured and displayed easily and accurately, including a capacitor power storage system that performs series-parallel connection switching.
[0007]
To this end, the present invention is a remaining capacity detection device for a capacitor power storage system that performs power storage by connecting a plurality of capacitors in series and parallel, and has a constant resistance at a low voltage and a plurality of constant voltage operations at a preset voltage. of the constant voltage limiting variable resistor circuit, and a load resistor on which the plurality of connected constant voltage limiting variable resistor circuit in series, and a current detecting means for detecting a current, the said plurality of constant voltage limiting variable resistor load a resistor and said current detecting means in series connected between the terminals of one capacitor of the plurality of capacitors, or, with the low level of a plurality of operating a constant voltage at a predetermined voltage having a constant resistance a constant voltage limiting variable resistor circuit, said comprising a plurality of load resistors which are respectively connected in series with a plurality of constant voltage limiting variable resistance circuit, and a current detecting means for detecting a current, each said load resistor straight A connected plurality of constant voltage limiting variable resistor circuit connected in parallel, and said current detecting means and circuits said parallel connection in series connected between the terminals of one capacitor of the plurality of capacitors, the The present invention is characterized in that the remaining amount of all capacitors of the capacitor power storage system is detected by the current detection means .
[0008]
In addition, a voltage follower is connected to the previous stage of the constant voltage limiting variable resistance circuit, and the plurality of capacitors are capacitors that are connected in series-parallel switching according to fluctuations in the output voltage of the capacitor power storage system. It is a feature.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing an embodiment of a remaining amount detection device for a capacitor power storage system according to the present invention, wherein 10 is a fuel gauge, C is a capacitor, R1 to R13 are resistors, X1 and X2 are shunt regulators, Q1 to Q4 represents a transistor.
[0010]
In FIG. 1A, a capacitor C is a capacitor power storage system configured by connecting a large number of capacitors in series and parallel, and a plurality of capacitors (cells) are connected in series to form a bank (module). Are connected in series to form a power supply device, the bank or a single capacitor constituting the bank, and the voltage between the terminals is taken out to display the remaining amount of the capacitor power storage system. The fuel gauge 10 is an ammeter with a full scale of 1 mA, for example, which displays the remaining capacity of a power supply device connected in series with a polygonal line approximation circuit at both ends of the capacitor C and connected with many capacitors. The shunt regulators X1 and X2 are temperature-compensated active Zeners and constitute an approximation circuit that performs broken line approximation together with the resistors R1 to R5. The shunt regulator X1 operates as a comparator by connecting a voltage dividing circuit composed of resistors R1 and R2 to a control input, and is turned on when the voltage of the control input reaches a predetermined voltage (bending point) (for example, manufactured by TI) TL431, NEC C1944, etc.). Therefore, the circuit composed of the shunt regulator X1 and the resistors R1 and R2 is a constant voltage limiting variable resistance circuit having a constant resistance at a so-called low voltage and operating at a constant voltage at a preset voltage, and the resistor 5 is a constant voltage limiting variable. It is a load resistance connected to a resistance circuit.
[0011]
The transistors Q1 and Q2 are high voltage transistors that form a voltage dividing circuit together with the resistors R6 to R8. When the withstand voltage exceeds the maximum rating of the shunt regulator, high voltage transistors Q1 and Q2 are used. This is a voltage follower (emitter follower) that uses β of the transistor to form a voltage dividing circuit with low active power consumption. For example, a voltage follower is formed by a fuel gauge for a full charge voltage of 10V. It can be applied to an arbitrary voltage of 10 V or more by adjusting the voltage dividing resistance before the first step and without re-adjusting the bending point. In other words, if a voltage dividing resistor is simply placed before the broken line approximation circuit, the bending point will be distorted, requiring recalculation or significant readjustment. However, if a voltage follower is connected before, the output impedance will be low. Therefore, even if an arbitrary voltage dividing resistor is connected before the element, the characteristic of the broken line approximation does not go wrong, and the design and adjustment are facilitated.
[0012]
In the case of a transistor having a small β, a Darlington connection of transistors Q3 and Q4 may be used as shown in FIG. In other words, a single transistor, a serially connected transistor as shown in FIG. 1 (A), or a Darlington-connected transistor as shown in FIG. It goes without saying. Further, the broken line approximation circuit may be configured by connecting shunt regulators X1 and X2 in parallel as shown in FIG.
[0013]
2 is a diagram showing a circuit configuration example of the high-voltage shunt regulator, FIG. 3 is a diagram showing characteristics of the high-voltage shunt regulator shown in FIG. 2, and FIG. 4 is a diagram showing characteristics of the broken line approximation circuit shown in FIG.
[0014]
A configuration example of a shunt regulator of about 100 V using a reference voltage of 2.5 V is a high voltage shunt regulator shown in FIG. In the circuit shown in FIG. 2, the voltage dividing point 3 is divided by a factor of 4 by the resistors R1 to R3. Therefore, when the collector side of the Darlington-connected transistors Q1 and Q2 is about 100V, the voltage is 25V. The control input of the shunt regulator X1 becomes 1/10 of 2.5V. Since this voltage is the operating point of the shunt regulator X1, as shown in FIG. 3, the collector potentials of the transistors Q1 and Q2 (marked with ▽ and Δ) are about 100V, the emitter potential of the transistor Q2 (marked with □ and ◇), The voltage of the shunt regulator X1 is maintained at 25V. Therefore, it shows the characteristic that the current (marked by ■, ◆) flowing through the resistor R4 increases in proportion to the increase in the remaining amount of the capacitor and the increase in the capacitor voltage.
[0015]
The example shown in FIG. 1 is a simple simultaneous equation in which another set of portions corresponding to X1, R1, and R2 in FIG. 2 having the characteristics of the above-mentioned broken line approximation is added in series and two bent portions are formed. As shown in FIG. 4, a very good broken line approximation characteristic (marked with ■) is obtained with respect to the capacitor characteristic (marked with □) as shown in FIG. In the circuit shown in FIG. 1 (A), the current supply element that gives the characteristic gives the current after the bending point {circle around (1)} R5 and the current before that {circle around (2)} blocks X1, R1, and R2, {3} Two of the blocks X2, R3, and R4 are in series, and three blocks are in series in total with (1).
[0016]
Even if these blocks are connected in parallel as shown in FIG. 1C, similar characteristics can be obtained. The design of the circuit is easier with the parallel type with less mutual interference, but the number of components increases somewhat as the resistors R11 to R13, which become loads, depending on the design value, and the current consumption increases.
[0017]
The remaining amount detection device according to the present invention can be similarly applied to a capacitor power storage system that performs bank switching. An example applied to a capacitor power storage system that switches banks will be described below. When bank switching is performed, the capacitor terminal voltage behaves differently in each bank. Therefore, generally, the remaining amount of all the capacitors of the power storage system can be known by providing fuel gauges in all the capacitor banks and adding them together. This method has already been filed.
[0018]
However, in the bank-switched capacitor power storage system, when attention is paid to a specific capacitor or capacitor bank, there is a certain relationship between the voltage between the terminals and the amount of power stored. A simple fuel gauge can be obtained by fitting the relationship with a broken line approximation circuit. This method does not measure the remaining amount of all capacitors, but estimates the total amount of electricity stored only from the target bank. Since the calculation is performed on the assumption that the capacitance of the capacitor is constant, the present method which assumes that the capacitance of each bank is constant has no problem in practical use as well.
[0019]
5 is a diagram showing a configuration example of a series-parallel bank switching type capacitor power supply device, FIG. 6 is a diagram showing discharge characteristics of the power supply device shown in FIG. 5, and FIG. 7 is a voltage and power storage of the capacitor power supply device shown in FIG. FIG. 8 is a diagram showing a configuration example of a shift type bank switching type capacitor power supply device, and FIG. 9 is a voltage and charge amount (remaining amount) of the capacitor power supply device shown in FIG. FIG. 10 is a diagram showing a configuration example of a tap type bank switching type capacitor power supply device. FIG. 11 is a diagram showing the relationship between the voltage of the capacitor power supply device shown in FIG. FIG.
[0020]
The series-parallel bank switching type capacitor power supply device shown in FIG. 5 connects capacitors C1, C2, C11, and C12 in parallel with parallel connection switches Sp1, Sp2, Sp11, and Sp12, for example, at full charge, and capacitors C1, C11. In this case, the fluctuation range of the output voltage out is reduced by sequentially switching to parallel connection when the voltage decreases with discharge, and in the case of charging, the opposite control may be performed. . In the series-parallel switching control, for example, as shown in FIG. 6, when the voltages of the capacitors C1, C2, C11, and C12 at full charge are 30V, the voltage at the output terminal starts discharging from 60V and decreases to 40V. First, the parallel connection of the capacitors C1 and C2 is switched to the series connection by the series connection switch Ss1. As a result, when the output voltage is raised to the same voltage of 60 V as when fully charged and further lowered to around 40 V by discharging, the parallel connection of the capacitors C11 and C12 is switched to the series connection by the remaining series connection switch Ss11. The change in the voltage at the output terminal (point 11 in FIG. 5) by such control is indicated by □ in FIG. 6, the change in the voltage at the capacitor C1 (point 3 in FIG. 5) is indicated by 図 in FIG. 6, and the capacitor C11 (FIG. 5). The change in voltage between points 13 and 1 is indicated by ▽ in FIG. 6 and the discharge amount is indicated by ■. Therefore, when the relationship between the voltage of the capacitor C1 (point 3 in FIG. 5) and the charged amount is shown on the basis of the characteristics shown in FIG. 6, the characteristics are as shown by □ in FIG. If this is approximated by a polygonal line, it can be set with considerably high accuracy, for example, by a polygonal line having two bending points ● shown by a one-dot chain line in FIG.
[0021]
The shift type bank switching type capacitor power supply device shown in FIG. 8 is also called a stagger type, and when fully charged, a series circuit of capacitors C1 and C2 and a series circuit of capacitors C3 and C4 are connected in parallel as shown in FIG. As the voltage decreases, the capacitors C1 and C4 are first switched to be connected in series to the parallel circuit of the capacitors C2 and C3 as shown in (c), and then all the capacitors C1 as shown in (d). , C2, C3, and C4 are switched so as to be connected in series. The change of the output voltage due to this switching is indicated by the solid line in FIG. 9, and the charged amount corresponding to the voltage of the capacitor C1 is indicated by the solid line in FIG. In this case as well, when approximated by a broken line, for example, a broken line having two broken points ● shown by a one-dot chain line in FIG. 9 can be set with considerably high accuracy.
[0022]
The tap type bank switching type capacitor power supply device shown in FIG. 10 is based on the capacitors C1 to C3, and the capacitors C4 and C5 are supplemented (for adjustment), and the base capacitors C1 to C3 are supplemented as the voltage decreases. The capacitors C4 and C5 are additionally connected in series step by step. In this system, it is possible to accurately measure the remaining amount with reference to the terminal voltages of the capacitors C1 to C3 that are the bases that are not switched. Since nonlinearity becomes remarkable when the capacitor C1 is relatively small, the capacitors C2 and C3 are omitted, three capacitors C1, C4, and C5 are used, and the terminal voltage V (1) of the capacitor C1 is expressed as X For the axis, □ in FIG. 11 shows the result of obtaining the ratio of the sum of the charged amounts of all capacitors to the full charge amount. In this case as well, when approximated by a broken line, for example, a broken line having a broken point ● shown by a one-dot chain line in FIG.
[0023]
In addition, this invention is not limited to the said embodiment, A various deformation | transformation is possible. For example, in the above-described embodiment, an example applied to three typical bank switching methods has been described. Through these various examples, attention is paid to a specific capacitor bank in a system in which bank switching is performed. When the relationship between the voltage and the energy storage amount of the entire system is examined and approximated by a polygonal line using the circuit of the present invention, it is clear that a simple and accurate fuel gauge can be obtained. Although a shunt regulator is used as the broken line approximation circuit, it goes without saying that it may be replaced with a Zener diode or other constant voltage control circuit or element.
[0024]
【The invention's effect】
As is apparent from the above description, according to the present invention, a remaining amount detection device for a capacitor power storage system that performs power storage by connecting a plurality of capacitors in series and parallel, and has a constant resistance at a low voltage and is preset. comprising a plurality of constant voltage limiting variable resistor circuit which operates based on a constant voltage at a voltage that is, a load resistor connected in series and a plurality of constant voltage limiting variable resistance circuit, and a current detecting means for detecting a current, a plurality of constant voltage limiting the variable resistance circuit between the load resistance and the current detecting means in series connected between one of the capacitor terminals of the plurality of capacitors, or a low voltage constant voltage at a preset voltage has a constant resistance a plurality of constant voltage limiting variable resistor circuit operating, comprising a plurality of load resistors connected in series with each of the plurality of constant voltage limiting variable resistance circuit, and a current detecting means for detecting a current, a load resistor each series A plurality of constant voltage limiting variable resistor circuit which is continued in parallel connection, the circuit and the current detecting means and said parallel connection in series connected between the plurality of one capacitor of the capacitor terminal, the current detecting means Since the remaining amount of all capacitors in the capacitor storage system is detected , even if it is a capacitor storage system that switches and connects multiple capacitors in series and parallel depending on the charge / discharge state, the remaining amount characteristics are approximated by a simple line can do. In addition, the remaining amount can be obtained and displayed accurately from the terminal voltage of one capacitor, and the configuration for detecting and displaying the remaining amount can be simplified and made compact.
[Brief description of the drawings]
FIG. 1 is a diagram showing an embodiment of a remaining amount detection device for a capacitor power storage system according to the present invention.
FIG. 2 is a diagram illustrating a circuit configuration example of a high-voltage shunt regulator.
FIG. 3 is a diagram showing characteristics of the high voltage shunt regulator shown in FIG. 2;
4 is a diagram showing characteristics of the broken line approximation circuit shown in FIG. 1. FIG.
FIG. 5 is a diagram illustrating a configuration example of a series-parallel bank switching type capacitor power supply device;
6 is a diagram showing discharge characteristics of the power supply device shown in FIG. 5. FIG.
7 is a diagram showing the relationship between the voltage of the capacitor power supply device shown in FIG. 5 and the amount of charge (remaining amount).
FIG. 8 is a diagram illustrating a configuration example of a shift type bank switching type capacitor power supply device;
9 is a diagram showing the relationship between the voltage of the capacitor power supply device shown in FIG. 8 and the charged amount (remaining amount).
FIG. 10 is a diagram illustrating a configuration example of a tap type bank switching type capacitor power supply device;
11 is a diagram showing the relationship between the voltage of the capacitor power supply device shown in FIG. 10 and the charged amount (remaining amount).
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Fuel gauge, C ... Capacitor, R1-R13 ... Resistor, X1, X2 ... Shunt regulator, Q1-Q4 ... Transistor

Claims (4)

A remaining capacity detection device for a capacitor power storage system that performs power storage by connecting a plurality of capacitors in series and parallel,
A plurality of constant voltage limiting variable resistance circuits that have a constant resistance at a low voltage and operate at a constant voltage at a preset voltage;
A load resistor connected in series with the plurality of constant voltage limiting variable resistance circuits;
Current detection means for detecting current, and a terminal of one of the plurality of capacitors in which the plurality of constant voltage limiting variable resistance circuits, the load resistance, and the current detection means are connected in series. connected between the remaining amount detecting apparatus of the capacitor power storage system and detects the remaining amount of the total capacitor of the capacitor power storage system by said current detecting means. A remaining capacity detection device for a capacitor power storage system that performs power storage by connecting a plurality of capacitors in series and parallel,
A plurality of constant voltage limiting variable resistance circuits that have a constant resistance at a low voltage and operate at a constant voltage at a preset voltage;
A plurality of load resistors connected in series with each of the plurality of constant voltage limiting variable resistance circuits;
Current detection means for detecting a current , wherein the plurality of constant voltage limiting variable resistance circuits each having the load resistance connected in series are connected in parallel, and the parallel connected circuit and the current detection means are connected to each other. and in series connected between the terminals of one capacitor of the plurality of capacitors, the remaining amount detecting apparatus of the capacitor power storage system and detects the remaining amount of the total capacitor of the capacitor power storage system by said current detecting means . The remaining amount detecting apparatus according to claim 1 or 2, wherein the capacitor power storage system is characterized in that to connect the voltage follower in front of the constant voltage limiting variable resistor circuit. 3. The remaining capacity detection device for a capacitor power storage system according to claim 1, wherein the plurality of capacitors are capacitors that are connected in series-parallel switching according to a change in output voltage of the capacitor power storage system.

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